Gas cooling device for compressed gas electric circuit breaker silencers



.A. CLERC Dec. 18, 1934.

GAS COOLING DEVICE FOR COMPRESSED GAS ELECTRIC CIRCUIT BREAKER SILENCERS Filed Sept. 1, 1952 Fig. 2

Patented Dec. 18, 1934 UNITED STATES .GAS COOLING DEVICE FOR COMPRESSED GAS LENCERS ELECTRIC CIRCUIT BREAKER SI- Andr Clerc, Villeurbanne, France, assignor to Ateliers de Constructions Electriques de Belle,

Paris, France Application September 1, 1932, Serial No. 631,385 In Germany October 19, 1931 5 Claims.

On the instant of striking a high intensity electric arc and during the whole duration of this arc, the energy suddenly liberated not only manifests itself in thermal and luminous fashion but also in the form of sound, and in particular by a real detonation which by its violence may be very objectionable. This phenomenon chiefly takes place in arcs developed in air such as for instance in circuit breakers in which the arc is extinguished by an air current into the external atmosphere or in open air fuses.

It has already been proposed to suppress the sonorous effect of these detonations by expulsing the gases through a special device. All these silencers create a certain back pressure prejudicial to the rapidextinction of the are. On the other hand this high pressure of the gases reduces the efliciency of the silencer.

The present invention remedies these two inconveniences. It consists in disposing in the path of the gases a group of ducts between the contacts and the silencer, and the gases on passing through these ducts abandon a part of their heat. This reduces the volume of the gases as well as their pressure, and consequently increases the efficiency of the silencer as also that of the circuit breaker.

The cooling ducts in accordance with this invention preferably communicate with a conduit or chamber at the outlet of which is disposed the silencer. The cooling ducts may be constituted by any solid members, such as for example by a mass of solid or perforated bodies disposed pellmell between two parallel gratings or by a series of tubes with axes parallel to the direction of the flow of the gases which penetrate into them. However the cooling ducts will preferably be constituted by a series of very thin metal plates disposed close together, parallel between them selves and to the direction of flow of the gases. The ducts thus formed can be further subdivided on their-outlet side by theuse of further shorter plates intercalated between those referred to above.

These cooling ducts can be used in conjunction with any type of silencer but seem to give best results when adapted to the specially constructed silencer described below:

The silencer is constituted by a mass of metal tubes disposed pell-mell in a chamber placed in front of the cooling ducts, the inlet and outlet sides of said chamber being perforated.

Small diameter and short length tubes will be preferably chosen. Experience has shown tubes of approximately equal length and external diameter.

As an example, and for purposes of illustration, two embodiments of the invention are shown in the attached drawing wherein:

Figure 1 is a sectional view of the apparatus embodying cooling plates, and

Figure 2 is a similar view showing cooling ducts instead of plates.

In the annexed drawing the hot gases of the arc following the direction of the arrow A penetrate by the conduit 1 into the flame cooling device 2 in the ducts of which the gases are cooled and contracted. They then traverse the chamber 5 and the silencer constituted by tubes 3 heaped pell-mell between the two gratings 4 and 4' each made up of a series of parallel plates similar to the plates 2 but of reduced length. Finally the gases pass through the openings in the grating 4 and are evacuated into the open air in the direction indicated by the arrow B. In certain cases one can also bring the grating 2 close up to the grating 4 in such manner as to suppress the chamber 5.

The dimensions of the whole device should evidently be such that the resistance to the flow of the gases shall be reduced to a negligible value.

The presence of the flame cooling device 2 disposed before the silencer allows a very appreciable reduction in the dimensions of this latter.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. In a circuit breaker, relatively movable contacts disposed in an enclosure, means to blow an electric are between these contacts by a compressed gas blast blown through the enclosure, metallic walled channels disposed in the enclosure adjacent the contacts and formed by thin metallic plates disposed parallel to the direction of blast, and screens disposed after said channels and defining with the wall of the enclosure a space filled with a small-bodied mass, the whole being arranged to permit the compressed gas-having blown the arc to escape in a straight line to the atmosphere by travelling in partial currents simultaneously through the metallic channels and thereafter through the interstices between the small-bodied mass.

2. In a circuit breaker, relatively movable contacts disposed in an enclosure, means to blow an electric are between these contacts by a comthat the most favourable efiect is obtained with pressed gas blast blown through the enclosure,

defining with the walls of the enclosure a p ce filled with a smallebodied mass, whereby to enable the compressed gas blowing the arc to escape in' a straight line to the atmosphere by successively issuing through the said channels in parallel partial currents and the interstices between the said small-bodied mass.

3. In a circuit breaker, relatively movable contacts arranged within an enclosure, means to blow an electric are between these contacts by a compressed gas blast travelling through the enclosure, metallic walled channels arranged in the enclosure next to the contacts, these channels being formed by plates parallel axially to the direction of the gas blast, and two screens disposed after these channels and defining with the walls of the enclosure a space filled with a small-bodied mass, whereby to enable compressed gas having blown an arc to escape in a straight line to the atmosphere by successively travelling through the metallic channels in partial parallel currents and the interstices between the small-bodied mass.

4. In a circuit breaker including, relatively movable contacts disposed in an enclosure, and means to blow an are between these contacts by a compressed gas blast travelling through the enclosure, and towards an exhaust passage, the combination therewith of metallic walled channels ar ranged in parallel relation to each other and to the direction of blowing in the exhaust passage and adjacent the contacts, and two screens disposed after the channels and defining with the walls of the exhaust passage a space filled with a mass of small metallic tubes, whereby to enable a gas blast travelling through the enclosure to escape to the atmosphere without direction changes by successively traversing the said metallic channels in partial parallel'currents and the interstices between the mass of said tubes.

5. In a circuit breaker, relatively movable contacts disposed in an enclosure, means to blow an are between these contacts by a compressed gas blast travelling through the enclosure, parallel metallic walled channels arranged in line with the direction of blowing within the enclosure and next to the contacts, and two screens disposed after the channels and defining with the walls of the enclosure a space filled with a mass of small metallic tubes, the height of these tubes being approximately equal to their outside diameter, whereby to enable a gas blast travelling through the enclosure to escape unhampered to the atmosphere by successively traversing the said parallel metallic channels and the interstices between the mass of said tubes. I

ANDRE CLERC. 

